<!DOCTYPE html>
<html lang="zh-CN">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>10rem适配方案</title>
    <style>
        /* 假设屏幕划分为15等份 */
        
        @media screen and (min-width:320px) {
            html {
                /* 320/15 */
                font-size: 21.33px;
            }
        }
        
        @media screen and (min-width:750px) {
            html {
                /* 750/15 */
                font-size: 50px;
            }
        }
        
        div {
            /* 大于320的屏幕 盒子尺寸42.66*42.66比例1:1 */
            /*大于750的屏幕 盒子尺寸100px*100px比例1:1 */
            width: 2rem;
            height: 2rem;
            background-color: forestgreen;
        }
    </style>
</head>

<body>
    <div></div>
</body>

</html>